Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267546
D. Niehaus, D. Andrews
The range of distributed real-time and embedded (DRE) system applications has continued to expand at a vigorous rate. Designers of DRE systems are constantly challenged to provide new capabilities to meet expanding requirements and increased computational needs, while under pressure to provide constantly improving price/performance ratios and shorter times to market. Recently emerging hybrid chips containing both CPUs and FPGA components have the potential to enjoy significant economies of scale, while enabling system designers to include a significant amount of specialization within the FPGA component. However, realizing the promise of these new hybrid CPU/FPGA chips will require programming models supporting a far more integrated view of CPU and FPGA based application components than that provided by current methods. This paper describes methods we are developing for supporting a multithreaded programming model providing strongly integrated interface to CPU and FPGA based component threads.
{"title":"Using the Multi-Threaded Computation Model as a Unifying Framework for Hardware-Software Co-Design and Implementation","authors":"D. Niehaus, D. Andrews","doi":"10.1109/WORDS.2003.1267546","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267546","url":null,"abstract":"The range of distributed real-time and embedded (DRE) system applications has continued to expand at a vigorous rate. Designers of DRE systems are constantly challenged to provide new capabilities to meet expanding requirements and increased computational needs, while under pressure to provide constantly improving price/performance ratios and shorter times to market. Recently emerging hybrid chips containing both CPUs and FPGA components have the potential to enjoy significant economies of scale, while enabling system designers to include a significant amount of specialization within the FPGA component. However, realizing the promise of these new hybrid CPU/FPGA chips will require programming models supporting a far more integrated view of CPU and FPGA based application components than that provided by current methods. This paper describes methods we are developing for supporting a multithreaded programming model providing strongly integrated interface to CPU and FPGA based component threads.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131953940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267527
Yunmook Nah, K. Kim, Taehyung Wang, Moon-hae Kim
Location-based service (LBS) systems have recently become a subject of active research and development. A key issue in such systems is efficient management of current and past location information of moving items. In the past two years, we have been establishing a new LBS system architecture, named the GALIS (Gracefully Aging Location Information System), which is based on the new approach of using a cluster of database server nodes and effecting efficient distributed and parallel computing in both real-time update of location records of moving items and processing of location-related queries. Each server node is dedicated to keeping records relevant to a different geographical zone and a different temporal zone. Each subsystem in GALIS is structured as a TMO network for the sake of easy analysis and expansion. A prototype implementation of GALIS has been realized only partially, and its full implementation is under way. In this paper, major features of GALIS are presented together with discussions on trade-off considerations which led to the adoption of those features. Issues remaining for further research are also briefly discussed.
{"title":"A Cluster-Based TMO-Structured Scalable Approach for Location Information Systems","authors":"Yunmook Nah, K. Kim, Taehyung Wang, Moon-hae Kim","doi":"10.1109/WORDS.2003.1267527","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267527","url":null,"abstract":"Location-based service (LBS) systems have recently become a subject of active research and development. A key issue in such systems is efficient management of current and past location information of moving items. In the past two years, we have been establishing a new LBS system architecture, named the GALIS (Gracefully Aging Location Information System), which is based on the new approach of using a cluster of database server nodes and effecting efficient distributed and parallel computing in both real-time update of location records of moving items and processing of location-related queries. Each server node is dedicated to keeping records relevant to a different geographical zone and a different temporal zone. Each subsystem in GALIS is structured as a TMO network for the sake of easy analysis and expansion. A prototype implementation of GALIS has been realized only partially, and its full implementation is under way. In this paper, major features of GALIS are presented together with discussions on trade-off considerations which led to the adoption of those features. Issues remaining for further research are also briefly discussed.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126091792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267501
R. Gandhi
In one of the modes of operation defined by the IEEE 802.11 standard, mobile stations are connected to a wired network via an access-point that serves as a bridge between the wireless and the wired networks. If an access-point fails, then, all of the mobile stations connected to a wired network via the access-point can lose connectivity. In this paper, we address the problem of enhancing the dependability of wireless networks by focusing on tolerating access-point failures. We develop and evaluate a new fault-detection approach, based on signal-to-noise ratio, that promises to be more effective than heartbeats. We also describe and compare three techniques to recover from access-point failures in 802.11 wireless networks.
{"title":"Tolerance to Access-Point Failures in Dependable Wireless Local-Area Networks","authors":"R. Gandhi","doi":"10.1109/WORDS.2003.1267501","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267501","url":null,"abstract":"In one of the modes of operation defined by the IEEE 802.11 standard, mobile stations are connected to a wired network via an access-point that serves as a bridge between the wireless and the wired networks. If an access-point fails, then, all of the mobile stations connected to a wired network via the access-point can lose connectivity. In this paper, we address the problem of enhancing the dependability of wireless networks by focusing on tolerating access-point failures. We develop and evaluate a new fault-detection approach, based on signal-to-noise ratio, that promises to be more effective than heartbeats. We also describe and compare three techniques to recover from access-point failures in 802.11 wireless networks.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114278055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267533
C. Fetzer, N. Suri
Transparent replication has been viewed as the holy grail of fault-tolerant computing. We discuss issues arising when using atomic broadcast to replicate services that are accessed via the Internet. We show how some of these issues can be addressed by the use of IP based replication schemes. In particular, we argue for the replication of services using a simple IP take-over scheme. Also, we show how a simple fail-over scheme can be combined with a load shedding and balancing mechanism.
{"title":"Practical Aspects of IP Take-Over Mechanisms","authors":"C. Fetzer, N. Suri","doi":"10.1109/WORDS.2003.1267533","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267533","url":null,"abstract":"Transparent replication has been viewed as the holy grail of fault-tolerant computing. We discuss issues arising when using atomic broadcast to replicate services that are accessed via the Internet. We show how some of these issues can be addressed by the use of IP based replication schemes. In particular, we argue for the replication of services using a simple IP take-over scheme. Also, we show how a simple fail-over scheme can be combined with a load shedding and balancing mechanism.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122559175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267526
H. Duran-Limon, G. Blair, A. Friday, Thirunavukkarasu Sivaharan, G. Samartzidis
A new class of applications can now be envisaged with the emergence of both mobile ad hoc computing and ubiquitous computing. Applications of such kind are characterised by being largely distributed and proactive, i.e. able to operate without human intervention. The anonymous and asynchronous paradigm, which is advocated by event models, has shown to be well-suited for this kind of applications. However, current real-time event-oriented middleware technologies do not provide a complete solution for the requirements of mobile ad hoc environments. In this paper, we present the research carried out on both a resource and a QoS management framework to achieve real-time support for an event system operating in mobile ad hoc environments. The framework makes use of both reflection and component technology. The implementation of our resource system is developed in OpenCOM, which is a lightweight, efficient and reflective model based on Microsoft’s COM.
{"title":"A Resource and QoS Management Framework for a Real-Time Event System in Mobile Ad Hoc Environments","authors":"H. Duran-Limon, G. Blair, A. Friday, Thirunavukkarasu Sivaharan, G. Samartzidis","doi":"10.1109/WORDS.2003.1267526","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267526","url":null,"abstract":"A new class of applications can now be envisaged with the emergence of both mobile ad hoc computing and ubiquitous computing. Applications of such kind are characterised by being largely distributed and proactive, i.e. able to operate without human intervention. The anonymous and asynchronous paradigm, which is advocated by event models, has shown to be well-suited for this kind of applications. However, current real-time event-oriented middleware technologies do not provide a complete solution for the requirements of mobile ad hoc environments. In this paper, we present the research carried out on both a resource and a QoS management framework to achieve real-time support for an event system operating in mobile ad hoc environments. The framework makes use of both reflection and component technology. The implementation of our resource system is developed in OpenCOM, which is a lightweight, efficient and reflective model based on Microsoft’s COM.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122822531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267499
R. Gumzej, W. Halang
Configuration management in distributed real-time systems and applications is considered. In particular, an idea for specifying the SW and HW architectures and modeling the dynamical behaviour of embedded real-time applications with timed hierarchical state diagrams is indicated. By their translation to program code, schedulable objects are formed, representing the applications’ semantics. A distinction is made between active and passive objects. Active objects communicate among each other and manage the passive objects and their co-operation. An active "super" object, called Configuration Manager, is foreseen for: the loading of the initial SW configuration onto its native processing node, any subsequent changes in the SW configuration, as well as inter-node co-operation.
{"title":"An Approach to Configuration Management and Co-Simulation in Distributed Embedded Systems","authors":"R. Gumzej, W. Halang","doi":"10.1109/WORDS.2003.1267499","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267499","url":null,"abstract":"Configuration management in distributed real-time systems and applications is considered. In particular, an idea for specifying the SW and HW architectures and modeling the dynamical behaviour of embedded real-time applications with timed hierarchical state diagrams is indicated. By their translation to program code, schedulable objects are formed, representing the applications’ semantics. A distinction is made between active and passive objects. Active objects communicate among each other and manage the passive objects and their co-operation. An active \"super\" object, called Configuration Manager, is foreseen for: the loading of the initial SW configuration onto its native processing node, any subsequent changes in the SW configuration, as well as inter-node co-operation.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131866726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267503
C. Reverte, P. Narasimhan
Assigning an application’s fault-tolerance properties (e.g., replication style, checkpointing frequency) statically, and in an arbitrary manner, can lead to the application not achieving its target resilience and performance. The resource management infrastructure that we have developed transparently determines a CORBA application’s resource usage and its rate/pattern of invocation across a distributed system. Using this information, our infrastructure makes more informed decisions about the application’s fault-tolerance properties, and dynamically adapts these decisions, as faults occur, and as resources are added and removed from the system. We have designed our prototype to be decentralized so that it is scalable and does not itself constitute a single point of failure.
{"title":"Decentralized Resource Management and Fault-Tolerance for Distributed CORBA Applications","authors":"C. Reverte, P. Narasimhan","doi":"10.1109/WORDS.2003.1267503","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267503","url":null,"abstract":"Assigning an application’s fault-tolerance properties (e.g., replication style, checkpointing frequency) statically, and in an arbitrary manner, can lead to the application not achieving its target resilience and performance. The resource management infrastructure that we have developed transparently determines a CORBA application’s resource usage and its rate/pattern of invocation across a distributed system. Using this information, our infrastructure makes more informed decisions about the application’s fault-tolerance properties, and dynamically adapts these decisions, as faults occur, and as resources are added and removed from the system. We have designed our prototype to be decentralized so that it is scalable and does not itself constitute a single point of failure.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122471963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267544
K. Kim
Techniques for systematic derivation of tight service time bounds of subsystems of distributed real-time embedded computing systems, are a key for enabling practical and highly meaningful certification of timeliness of systems, which is the most challenging part of the reliability certification process. An approach which uses a hybrid of measurement-based statistical derivation approaches and worst-case analysis approaches in deriving tight service time bounds, is proposed. The use of this hybrid approach together with a divide-and-conquer strategy in deriving the service time bounds of complex systems, is also proposed. Major research issues that need to be resolved before the hybrid approach can be practiced are mentioned.
{"title":"Timeliness Assurance via Hybrid Approaches during Design of Distributed Embedded Computing Systems","authors":"K. Kim","doi":"10.1109/WORDS.2003.1267544","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267544","url":null,"abstract":"Techniques for systematic derivation of tight service time bounds of subsystems of distributed real-time embedded computing systems, are a key for enabling practical and highly meaningful certification of timeliness of systems, which is the most challenging part of the reliability certification process. An approach which uses a hybrid of measurement-based statistical derivation approaches and worst-case analysis approaches in deriving tight service time bounds, is proposed. The use of this hybrid approach together with a divide-and-conquer strategy in deriving the service time bounds of complex systems, is also proposed. Major research issues that need to be resolved before the hybrid approach can be practiced are mentioned.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"462 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120897408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267524
S. Arbanowski, S. Steglich, I. Radusch, R. Popescu-Zeletin
The goal of ‘I-centric Services based on Super Distributed Objects’ is to provide a seamless computing environment on the basis of users’ individual communication spaces. It controls and manages large numbers of autonomous and decentralized objects (Super Distributed Objects), in individual living or working spaces providing services that can adapt to users’ individual requirements (I-centric Services). This paper introduces the I-centric Communications approach and identifies the requirements and design of Super Distributed Objects as the paradigm for future pervasive and autonomous systems. Results of this project have been adopted by the World Wireless Research Forum (WWRF) and Object Management Group (OMG)
{"title":"Super Distributed Objects: An Execution Environment for I-Centric Services","authors":"S. Arbanowski, S. Steglich, I. Radusch, R. Popescu-Zeletin","doi":"10.1109/WORDS.2003.1267524","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267524","url":null,"abstract":"The goal of ‘I-centric Services based on Super Distributed Objects’ is to provide a seamless computing environment on the basis of users’ individual communication spaces. It controls and manages large numbers of autonomous and decentralized objects (Super Distributed Objects), in individual living or working spaces providing services that can adapt to users’ individual requirements (I-centric Services). This paper introduces the I-centric Communications approach and identifies the requirements and design of Super Distributed Objects as the paradigm for future pervasive and autonomous systems. Results of this project have been adopted by the World Wireless Research Forum (WWRF) and Object Management Group (OMG)","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"236 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127532119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-10-01DOI: 10.1109/WORDS.2003.1267529
R. B. Correia, L. Carmo, Edmundo L. Cecilio, L. Bacellar, L. Pirmez
In the past few years the massive deployment of real-time multimedia services has motivated the research community to investigate new quality of service (QoS) mechanisms to overcome the limitations of IP networks. Since assured levels of service must be provided, these mechanisms should interact flexibly with network performance management systems. When such integration is achieved, it is possible to trigger actions effectively to prevent QoS failures and simultaneously to balance network load. Mechanisms for rerouting traffic flows of QoS critical applications may be employed to support performance management systems in satisfying the application requirements. In addition, proactive actions could be taken before applications are affected by QoS failures. To meet these goals, a proactive network management and rerouting framework is introduced. The proposed framework is based on active technology and aims at providing the means needed for establishing new routes with sufficient resources for traffic flows of QoS critical distributed applications. A system prototype using the proposed framework was implemented and test results show that its deployment is feasible considering the hardware processing capability available today.
{"title":"A Proactive Management and Rerouting Framework for QoS Critical Distributed Applications Using Active Technology","authors":"R. B. Correia, L. Carmo, Edmundo L. Cecilio, L. Bacellar, L. Pirmez","doi":"10.1109/WORDS.2003.1267529","DOIUrl":"https://doi.org/10.1109/WORDS.2003.1267529","url":null,"abstract":"In the past few years the massive deployment of real-time multimedia services has motivated the research community to investigate new quality of service (QoS) mechanisms to overcome the limitations of IP networks. Since assured levels of service must be provided, these mechanisms should interact flexibly with network performance management systems. When such integration is achieved, it is possible to trigger actions effectively to prevent QoS failures and simultaneously to balance network load. Mechanisms for rerouting traffic flows of QoS critical applications may be employed to support performance management systems in satisfying the application requirements. In addition, proactive actions could be taken before applications are affected by QoS failures. To meet these goals, a proactive network management and rerouting framework is introduced. The proposed framework is based on active technology and aims at providing the means needed for establishing new routes with sufficient resources for traffic flows of QoS critical distributed applications. A system prototype using the proposed framework was implemented and test results show that its deployment is feasible considering the hardware processing capability available today.","PeriodicalId":350761,"journal":{"name":"2003 The Ninth IEEE International Workshop on Object-Oriented Real-Time Dependable Systems","volume":"234 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132731101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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